Boiler



(No Model.)

BOILER.

No. 399,941. Patnted Mar. 19, 1889.I

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JAMES T. SMITH, OF BALTIMORE, MARYLAND..

BOlL-ER.

SPECIFICATION forming part of Letters Patent No. 399,941, dated March 19, 1889.

Application filed November 22, 1888. Serial No. 291,611. (No model.)

To all whom it may concern:

Be it known that I, J AMEs T. SMITH, of the city of Baltimore and State of Maryland, have invented certain Improvements in Vertical Water-Tube Boilers, of which the following is a specification.

In the description of the said invention which follows reference is made to the accompanying drawings, forming a part hereof, and in Which- Figure l is an exterior side elevation of the improved boiler with a portion of the outer shell thereof removed, and Fig. 2 a central vertical section of the same. Fig. 3 is a crosssection of the improved boiler, taken on the dotted line c, Fig. 2. Figs. at and 5 are detail views of couplings for securing the tubes, on an enlarged scale.

Similar letters of reference indicate similar parts in all the gures.

In the said drawings, A represents the outer J shell of the boiler, which is cylindrical and y provided with a spherical head.

B is a cylindrical fire-box secured at its lower end to the shell by means of the leg C. The crown of the fire-box is spherical in shape, and is preferably cast of steel. In the center of the crown of the fire-box is a hole having a iiange, a, to which is riveted the upper and open end of the cylindrical heater D. The lower end of this heater is spherical in form and situated below the grate-bars E.

F F are water-tubes which connect the side vof the heater at a point above the grate-bars and the crown or' the ire-boX are bored out to a size considerably larger than the outside of the tube, and the connection completed by Ineans of the two nuts c, one on each side of the sheet. These nuts are provided with inner projections, CZ, which approach each other and are tightened on a washer made of some compressible material adapted to resist considerable heat, such as wood or paper. By this means the connection between the tubes and the boiler proper is rendered water-tight.

In view of the spherical shape of the crownsheet of the fire-box, I provide the same at such points or places as receive the tubes F with an upper and a lower boss, respectively denoted by q and h, the faces of which p are parallel with each other.

G G are straight tubes arranged radially around the heater D to connect the heater with the water-space between the Fire-box and the outer shell below the grate-bars.. The water in these tubes being cooler than that in the curved ones, a complete circulation of water through the boiler in the direction indicated by the arrows is maintained.

I-I is a smoke-pipe extending from the fire' box head through the spherical top of the shell. The'boiler is provided with tire-doors of the usual kind', and also with a stand, J, which Inay be of any desirableA construction.

In a vertical cylindrical boiler, a centrallyplaced lire-box having a heater dependent from its crown, combined with a series of water-tubes which connect the side of the said heater with the crown of the fire-box, and another series of water-tubes which unite the lower end of the said heater with the waterspace around the said fire-box, substantially as and for the purpose specied.

JAMES T. SMITH.

Witnesses:

WM. T. HOWARD, H. M. FITZHUGH. 

